Symbian any day. Reasons stated below:
1. Fast like nothing else. Just try to play a 480p video in an N8 and Optimus, and you will know what i mean. By the time the Android starts playing the Nokia will have elapsed 10 seconds of the video.
2. Wide Application base for the Symbian is something your 14 year old kid will tell you about. So nothing comes close to S60.
3. Having said that, it also stands to be said that since Symbian is used by Nokia phones, they have better durablity quality and features than any Samsung phones. Check out the specs of the N8 for proof.